1. Field of the Invention
Hollow wheels and their hollow cages are devices which enable transfers of fluid, exploitation of the energy they contain, or use of the forces they exert.
2. Description of Related Art
The development of hollow wheels and their static cages has been slowed due to their very complex forms, which must be designed and adapted for each concerned application, and until now it was not possible to design them easily in quantity in order to be able to test and optimize them.